Vulnerability in Yhirose Cpp-Httplib
CVE-2026-32627
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.2, when a cpp-httplib client is configured with a proxy and set_follow_location(true), any HTTPS redirect it follows will have TLS certificate and hostname verification silently disabled on the new connection. The client will accept any certificate presented by the redirect target — expired, self-signed, or forged — without raising an error or notifying the application. A network attacker in a position to return a redirect response can fully intercept the follow-up HTTPS connection, including any credentials or session tokens in flight. This vulnerability is fixed in 0.37.2.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (16.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Yhirose Cpp-Httplib — versions < 0.37.2
Weakness classification (CWE)
References
- github.com/yhirose/cpp-httplib/security/advisories/GHSA-c3h8-fqq4-xm4g (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-32627?
- CVE-2026-32627 is a high-severity vulnerability in Yhirose Cpp-Httplib, classified under Improper Certificate Validation. CVSS score: 8.7/10. Published 2026-03-16.
- How severe is CVE-2026-32627?
- High severity. CVSS v3 base score is 8.7 out of 10.